How to cook
Beat the eggs with the butter, oil and sugar. Add the flour along with the vanilla, baking powder, yoghurt.
If you feel that the mixture is way too runny, add some more flour, but the actual blend for the muffins must be more watery than your usual cake batter.
Finally, stir with coarsely chopped walnuts and chocolate chips. Pour the mixture 2/3 of the way up to the prepared muffin cups. Bake for about 25 minutes or until done.